Biological Molecules: DNA Replication Flashcards
what is the type of replication?
semi-conservative replication
what does semi-conservative replication of DNA ensure?
ensures genetic continuity between generations of cells
what is the process of DNA replication?
- unwinding of the double helix and the breakage of hydrogen bonds between complementary bases in the polynucleotide strands = DNA helicase
- attraction of new DNA nucleotides to exposed bases on template strand and base pairing
- joining of adjacent nucleotides by condensation reaction = DNA polymerase
what is DNA helicase?
- unwinds the DNA and break hydrogen bonds between bases
what is DNA polymerase?
- joins adjacent nucleotides
- forms phosphodiester bonds
- forms the sugar-phosphate backbone
- catalyses condensation reactions
who can validate the semi-conservative replication of DNA proposed by Watson and Crick?
Meselson and Stahl
what did Meselson and Stahl do?
- N14 and N15
- allowed on round of DNA replication, then retrieved DNA sample by spinning in a centrifuge
what is the name of the bond between complementary base pairs?
hydrogen bonds
what is the name of the bond between adjacent nucleotides in a DNA strand?
phosphodiester bonds
what enzyme is involved in DNA replication?
DNA helicase and DNA polymerase
what is the role of the single- stranded DNA fragments (using knowledge of semi conservative replication)?
acts as a template strand
- determines the order of the nucleotides
what is the role of the DNA nucleotides (using knowledge of semi-conservative replication)?
- forms complementary pairs between A-T and C-G
what 2 features of DNA are important in semi-conservative replication?
- two strands, so both can act as template strands
- complementary base pairing allows accurate replication of DNA
